1. Field of the Invention
The present invention relates to a method and apparatus for acquiring an image with an increased dynamic range by using an electronic shutter of a camera.
2. Description of the Related Art
High Dynamic Range (HDR) imaging is a technology for improving image quality by increasing a dynamic range of an image output from an image sensor of a camera device. If a bright area and a dark area are included in a single image, there is a limitation in obtaining better image quality due to a limited dynamic range of the image sensor.
An imaging device acquires an image by converting light gathered by a sensor into an electrical signal. Although the imaging device photographs a real scene, an image acquired by the imaging device may be darker or brighter than the actual scene according to a light-gathering time (exposure time). That is, the longer the imaging device is exposed to light, the brighter the image obtained. Accordingly, a light-gathering time in a dark area seems to be short, and a light-gathering time in a bright area, that is, where light is saturated, seems to be long. In particular, since an 8-bit digital image has only grayscale levels between 0 and 255, a dynamic range of the digital image is limited.
Accordingly, HDR imaging for increasing a dynamic range by synthesizing a plurality of images with different exposure amounts is necessary.